Rubber heel



G. H. wlLLlS July 23, 1929.

RUBBER HEEL Filed July 2' 1928 Patented duly 23,1929.; l

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GLENN n. W1Lras,on'annon,onfo, As'srenon 'ro JOHN L. snrnnn, or AKRON, omo.

RUBBER HEEL.

.application filed :'ruiya,

This invention relates to laminated rubber material or articles such as rubber shoe treads and particularly heels, of the type employing a non-metallic attaching layer,

5 My object in connection with heels and -the like is to dispense with the use ofA embedded metallic Washers now commonly employed for the purpose of retaining` the nail'head's, thus reducing the labor' cost, and at the same vtime to avoid the objections Ato other substitutes which have been proposed such as Wood, fiberizedvrubber, or rubberized cloth, which detract from the flexibility and resiliencyof the heel or exhibit-other disadvantages such as relatively-poor adhesion between the cushion body vand the attaching layer.

In the preferred mode of practicing the invention employ a heel having the usual concave seating face in' Which` is inserted afieX- ible, resilient inlay of rubber composition including an intermixture gf elongatedon iliform organic reinforcing materialcapable `of imparting to the inlay a leathery firmness Without greatly Jsuppressing its rubbery characteristics. This inlay or attaching layer is joined to the rubber cushion body With an inseparable vulcanized bond and serves as an effective means of retaining the nail heads,

preventing spreading of the heel and obtainl ing a tight seating at the edges.

Of the accompanying drawings, Fig. 1 is a top planvieW of a rubber heel embodying my invention.

Fig. 2 is a perspective view of the attache,

:i5 ing plug or layer.

Fig. 3 is a sectional View of a portion of a heel mold containing the heels; Which are Vshown in transverse section.

ln the drawings, 10 is the resilient heell tu body composed of a suitable' rubber com-4 pound such as good reclaimed rubber, With or Without new rubber, and containing the usual pigments, sulphur for vulcanization and accelerator. i f

The' attaching layer is a shallow inlay or plug 11 composed of rubber compound of about the same uality as the body compound, or it may be a c eaper quality, together with an intemixture of organic reinforcing ma- 59 terial capable of imparting to the vulcanized compound aiirmness resembling that of oaktanned sole leather, but Without entirely suppressing its rubbery characteristics-including resiliency and capability of forming an inseparable vulcanized bond with the body rubber. rlhe reinforcing material is indition.

192s. serial iro. zsavas.

cated' at 12, homogeneously distributed throughout the rubber compound-used in the plug 11.'

The plug or layer 11 is located in the mold 13 with the aid of guide pins 14 on the lower mold plate, so that it will retain its-proper position in the seating face of theheel under the-pressure ofthe molding operation. The

bedded flush-in the seating portion'r face;

The seating face of the heel being shaped.

in concave form in the usual manner, as indicated in'Fig. 3, the attaching layer-11 acts like a stiff spring when the heel is nailed down to its seat on the shoe, and the softer edges of the body rubber coact therewith to insure a tight seating all around'.

The guide pins are located outside of the usual "nailing zone or area which surrounds the central area ofthe'attaching face so as to leave said nailing area imperforate, this `being a construction which l prefer because it avoids having to place the nails accurately at predetermined points in said nailing zone.

Any other desired means for holding ,the

compared with soft animal or vegetableg* iibers such as cotton, wool, etc.; and' of these,

the one l consider 'the'bst on account of its cheapness and general suitability for the purpose is common hog hair. rlhis is usedin the proportion Vof `tapproaimabely 30%' on the total Weight ofthe compound in the layer 11, but this proportion is subject tosome varia o In this connection, animal hair is sharply distinguished from vegetable fibers likecotton and from asbestos, on account of its'coarseness and marked springiness or repound of the heel body.

The rubber stock in the layer 1l, formixing purposes, shouldbe made rather soft or sappy as by the use of about 5 to 6%` of a flux or softener such as cottonseed oil, palm oil or a Suitable mixture of vegetable rand I, mineral oi1s,`i`n` order to facilitate the dis tribution of the hair throughout said stock;

Milling is preferably performed on evenspeed rolls having an open setting to avoid a bank,fand the hairis vfed to the space be-r tween the rolls into the plastic sheet .which follows one ofV said rolls, the opening being increased asthe volume builds up. It results from this method of incorporating the hair that the latter retains substantially the eil'ective length in the compound which it had before being introduced thereto.A That is, if hog hairs of the ordinary'length of from 1/2 inch to 3' inches and averaging about11/2 inches are used, it. Will be foundthat this process off- 'milling'breaks'l only the longer ones, leaving the shorter onesnnbrokenaand the average hair length after milling the compound will be nearly 1 inch. A hair only 1/2 inch long is so iirmly anchored 'in the rubber that it cannotfbe pulled' out Without breaking.

' When a homogeneous lmixture has beenpobtained,the compound. is run into a sheet'of the desired thickness and flat blanks or plugs "11 ofthe shape shown in Fig.v l2 are died out of said sheet.` These plugs arethen assem- V bled in the mold 13 with the ybody rubber in With the common type having embedded me any suitable manner and the heels vulcanized as already described. Y Y

A .heel constructed as above set forth can beglmade at a reduced labor cost as compared tallic washers, and they results are superior, 4a

not only in comparison with such type-but also as compared with heels employing other substitutes for Washers which have heretofore f been proposed.. The nails readily penetrate the layer 1 1 but their heads are effectively re- 50` l tained thereby, an inseparable bond with the body rubber is Obtained, the stiffness of the layer lly prevents the attached heel' from 'spreading and contributes to a tight seating at thel edge, and the heel asa Whole, includa 5,5

ing the attaching layer, isboth iexible and resilient.

l. A co1nposite', vulcanized-rubber shoe tread vvhich is flexible andresilient throughout, said tread comprising a rubber cushion wearing body, and an attaching layer of -leatheryrfirmness integrally vulcanized to 4said cushion body and formed of rubber intermiXed with. relatively-long animal hair, f said layer being adapted to retain nail heads and resist the lateral spreading tendency of thecushion body.

2, A composite, vulcanized-rubber .heel

- compri-sing a .rubber cushion body, and a tlex- 70 ible, resilient, attaching layer integrally united With and inlaid .in the seating face of said body, said layer being composed of rub-4 f ber compoundcontaining a minor proportion of animal hair having substantially the stiil'- 75V ness of hog hair.

3'. A composite vulcanized-rubber heel comprising .a rub er cushionj body, and a ex-ible, resilient, attachin i layer integrally united with and inlaid-in t e seating face of.

said body, said layer being composed of rubber compound containing a minorproport'ion of animal hair having substantially the sti-lil ness of hog hairand ofan average length on not less than onefha-lf inch.

In Witness whereof I have hereunto set my hand this-29th day of June, 1928.A

' V GLENN H. WILLIS.- 

